CHG: adjusted timing according to @sentinel 's traces

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 7e31f53dcccb66b04e3c5d04b809cf5f20308477..ff80b8b341e538a17780756541268f497dce106e 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -84,7 +84,9 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
                        case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
                        case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
                        default: //test parity
                        case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
                        case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
                        default: //test parity

-                               if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
+                               if (parityTest(parityWd, pLen, pType) == 0) 
+                                       return 0; 
+                               break;

                }
                bitCnt+=(pLen-1);
                parityWd = 0;
                }
                bitCnt+=(pLen-1);
                parityWd = 0;


@@ -148,8 +150,11 @@ uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
 uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
 {
 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
 uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
 {

-       uint8_t foundCnt=0;
-       for (int idx=0; idx < *size - pLen; idx++){
+       // Sanity check.  If preamble length is bigger than bitstream length.
+       if ( *size <= pLen ) return 0;
+       
+       uint8_t foundCnt = 0;
+       for (int idx = 0; idx < *size - pLen; idx++){

                if (memcmp(BitStream+idx, preamble, pLen) == 0){
                        //first index found
                        foundCnt++;
                if (memcmp(BitStream+idx, preamble, pLen) == 0){
                        //first index found
                        foundCnt++;